Current strategies in regenerative medicine aim towards replacing tissue that undergoes an increased apoptosis rate. That means that within the organ there is a net loss of functional cells because more cells are dying than are being replaced. Therefore, the transfer of regenerative cells, e.g., stem cells and progenitor cells, from one location to the site of renewal is a therapeutic approach to restore the organ back to an equilibrium. Research at our laboratories has shown that stem cells and regenerative cells are present in every organ, primarily located in the vascular and perivascular space with the early progenitor cells in the vessel wall attached to the lamina elastica interna. One population of these cells is able to replace the stroma of an organ, the other part of these cells is capable to differentiate into the respective parenchym of the specific organ. Each organ can be compared to a house, where the stroma made from fibroblasts and consisting of extracellular matrix can be compared to walls of bricks and mortar in a house, the piping in a house corresponds to blood vessels of the organ and nerves represent the electrical wiring in the walls. Inside these houses, in each organ one has a certain type of inhabitants, such as liver cells, heart cells, bone cells, cartilage or fat cells, also called the parenchym of an organ.
In order to restore function to a dysfunctional organ, it is important to provide both the stroma, that means the housing that form the walls of the organ and the inhabitants, which are the specific parenchymal cells.
A simple means to recover the regenerative cells capable of restoring organ function is to dissociate them from subcutaneous fat tissue, because it is rich in blood vessels and the removable adipose tissue is not essential for life. Most people are capable, even happy, to donate several grams of those tissues.
Autologous grafting of tissue harvested by lipoaspiration is a common procedure in cosmetic surgery for both small (e.g., nasolabial folds) and large (buttocks or breast) volume filling applications. The primary benefits of this procedure termed “autologous fat grafting” are lower cost versus synthetic fillers and no immune rejection since the patient's own tissue is used. Currently, multiple methods of lipoaspirate collection and processing are employed to obtain tissue for grafting. Factors that determine clinical outcomes following autologous fat grafting have not been fully elucidated. However, it is widely recognized that improving the persistence of the graft is an area of significant need.